This is a phase III trial of Zoledronate, a third generation bisphosphonate which is a more potent inhibitor of osteoclasts than earlier bisphosphonates, in two dose levels verskus pamidronate (Aredia). The latter drug has been shown (in combination with anti-neoplastic agents) to decrease significantly the proportion of patients with skeletal complications due to lytic bone disease associated with multiple myeloma and breast cancer.